Game suddenly capped at 30fps

The game usually used to run on a constant 120fps, but suddenly it can’t seem to get higher than 30. I tried restarting my pc and resetting my graphic card yet it’s still the same. I’ve also tried to repair the game, but the issue is still the same.
I don’t know why this is happening.

Please tell me how to fix this, I can’t play the game like this.

Update: Okay so Ive just tried setting the game to borderless windowed mode and the fps went back up to normal. But the game feels laggy and twitchy to play in like this. I switched it back to fullscreen and the fps dropped back down. I usually always have it in fullscreen, and have never experienced this issue up until now.

Hi, Rain! o/

The two main FPS locks are V-sync and the FPS lock option, both in the game settings. If you are getting this only in full-screen I would bet on V-sync being the cause, so try to change this setting.

You can also try to reset the game settings, and the GPU settings.